Collection and Preparation of Samples

Break off both ends of the XAD-4 sorbent sampling tube. Position the backup section of XAD-4 resin nearest the pump and connect to the pump 

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Finally, one aspect that can pay a role in compositional studies is the sieve (screening) analysis. Like all petroleum products, sampling is, or can be, a major issue. If not performed correctly and poor sampling is the result, erroneous and very misleading data can be produced by the analytical method of choice. For this reason, reference is made to standard procedures such as the Standard Practice for Collection and Preparation of Coke Samples for Laboratory Analysis (ASTM D346) and the Standards Test Method for the Sieve Analysis of Coke (ASTM D293). 

The collection and preparation of water samples requires individual approaches for different analytical tasks. If heavy metals or long-lived radionuclides at the trace and ultratrace concentration range are to be determined in water samples by ICP-MS, especially careful sampling is necessary to avoid possible contamination (using clean bottles and containers washed and cleaned before use, for example, with 2 % nitric acid and high purity water to stabilize traces in the samples), and the loss of analyte by adsorption effects or precipitation should be also considered. 

In contrast to external validation, internal validation involves the use of the calibration data only, and does not require the collection and preparation of additional validation samples. There are several different techniques that are considered internal validation techniques, and these are mentioned in the following sections. 

ASTM D-346. Standard Practice for Collection and Preparation of Coke Samples for Laboratory Analysis. 

Brown and Reinsch [15] have discussed the collection and preparation of soil samples for the US Federal Soil Survey Laboratory Programme. 

Utility and HVAC systems are among the easiest to address with respect to revalidation. Their performance is evaluated on a near continuous basis through the collection and testing of samples taken from the system. This affords a direct and ongoing assessment of the system s acceptability for use. Coupled with effective change control, calibration, and preventive maintenance programs, the collected data from the system should support its continued use. The preparation of summary reports on results from the system on a monthly or quarterly basis precludes the need for further evaluation. 

The OPCW mobile laboratory is designed for use in all types of inspections. It is able to function self-contained, if necessary in a tent powered by electricity generators. It contains sufficient equipment to allow the IT the collection and preparation of various types of sample matrices and the GC/MS analysis of their extracts. All items of equipment are packaged in flight cases in such a way that two persons can move each transport container by hand. 

It is vital that environmental samples (such as effluents, leachates, receiving waters, sediments and soils) taken for testing with bioassays are considered representative and that the procedures adopted for the collection, storage and preparation of samples ensure that the toxicity of the sample obtained at source does not change markedly before a test is conducted. It is also vital that supporting documentation, in the form of a chain of custody record, accompanies the sample. 

The authors would like to thank to all the technical staff involved in collecting and preparing of the samples and to the commercial companies which allowed this research activities in their fishing areas. 

Since the focus of this book is the analysis of collected samples, only integrated samples will be considered here. Furthermore, this chapter will look only at the collection and preparation of gaseous samples. The collection of particle and liquid samples will be considered in the following chapter. Because of their complexity, most of the discussions in this chapter will center on the collection and analysis of atmospheric samples, however, the principles involved relate to any gaseous sample. 

Samples collected for spectral analysis, can typically be classified into three categories (1) solids, (2) liquids, and (3) gases. This chapter deals strictly with the collection and preparation of solid and Uquid samples as other chapters describe the collection and sample preparation of gases. 

Sample Collection and Preparation of Liquid and Solids 29 Table 2.2 Various sample preparation methods for solid samples. 

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